Electrical Components Attached to Fabric

ABSTRACT

An item may include fabric having insulating and conductive yarns or other strands of material. The conductive strands may form signal paths. Electrical components can be mounted to the fabric. Each electrical component may have an electrical device such as a semiconductor die that is mounted on an interposer substrate. The interposer may have contacts that are soldered to the conductive strands. A protective cover may encapsulate portions of the electrical component. To create a robust connection between the electrical component and the fabric, the conductive strands may be threaded through recesses in the electrical component. The recesses may be formed in the interposer or may be formed in a protective cover on the interposer. Conductive material in the recess may be used to electrically and/or mechanically connect the conductive strand to a bond pad in the recess. Thermoplastic material may be used to seal the solder joint.

This application is a continuation of U.S. patent application Ser. No.17/184,927, filed Feb. 25, 2021, which is a continuation of U.S. patentapplication Ser. No. 16/914,131, filed Jun. 26, 2020, now U.S. Pat. No.10,959,331, which is a continuation of U.S. patent application Ser. No.16/685,846, filed Nov. 15, 2019, now U.S. Pat. No. 10,701,802, which isa continuation of U.S. patent application Ser. No. 15/439,641, filedFeb. 22, 2017, now U.S. Pat. No. 10,485,103, which claims the benefit ofU.S. provisional patent application No. 62/298,050, filed on Feb. 22,2016, all of which are hereby incorporated by reference herein in theirentireties.

FIELD

This relates generally to items with fabric and, more particularly, toitems with fabric and electrical components.

BACKGROUND

It may be desirable to form bags, furniture, clothing, and other itemsfrom materials such as fabric. Fabric items generally do not includeelectrical components. It may be desirable, however, to incorporateelectrical components into fabric to provide a user of a fabric itemwith enhanced functionality.

It can be challenging to incorporate electrical components into fabric.Fabric is flexible, so it can be difficult to mount structures tofabric. Electrical components must be coupled to signal paths (e.g.,signal paths that carry data signals, power, etc.), but unless care istaken, signal paths will be damaged or components may become dislodgedas fabric is bent and stretched.

It would therefore be desirable to be able to provide improvedtechniques for incorporating electrical components into items withfabric.

SUMMARY

An item may include fabric such as woven fabric having insulating andconductive yarns or other strands of material. The conductive yarns mayform signal paths (e.g., signal paths that carry data signals, controlsignals, power, etc.). Electrical components can be embedded withinpockets in the fabric and may be electrically coupled to the signalpaths.

Each electrical component may have an electrical device such as asemiconductor die that is mounted on an interposer. The electricaldevice may be a light-emitting diode, a sensor, an actuator, or otherelectrical device. The electrical device may have contacts that aresoldered to contacts on the interposer. The interposer may haveadditional contacts that are soldered to the signal paths. Metal tracesin the interposer may convey signals (e.g., data signals, controlsignals, power, etc.) between the contacts to which the electricaldevice is coupled and the contacts to which the conductive strands arecoupled.

The interposer may be formed from a printed circuit such as a rigidprinted circuit substrate layer or a flexible printed circuit substratelayer, or may be formed from both rigid and flexible printed circuitsubstrate layers.

To create a robust connection between the electrical component and thefabric, the conductive strands may be threaded through recesses,trenches, or openings in the component. The recesses, trenches, oropenings may be formed in the electrical device itself, in theinterposer to which the electrical device is mounted, or a protectivecover that encapsulates portions of the electrical device andinterposer. Conductive material in the recess may be used toelectrically and mechanically connect the conductive strand to a bondpad in the recess.

In arrangements where strands are threaded through an interposer, arecess may be formed from a gap between upper and lower substrates inthe interposer or from a notch that extends from an upper surface to alower surface of the interposer.

In arrangements where strands are threaded through a protective cover, atrench may be formed from a gap between upper and lower protectivecovers or from a notch that extends from one edge of the protectivecover to an opposing edge of the protective cover. The notch may havelocally widened portions to help prevent the solder from shifting off ofthe bond pad in the trench. The trench may have straight or slopedsidewalls.

Thermoplastic material may be formed in the trenches. Heat may beapplied to reflow solder in the trench and melt the thermoplasticmaterial. Once cooled and hardened, the solder may form a secureelectrical connection between the strand and the pad, while thethermoplastic may spread across the trench and provide a seal thatprotects the electrical connection from mechanical damage andenvironmental contaminants.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an illustrative fabric item inaccordance with an embodiment.

FIG. 2 is a side view of illustrative fabric in accordance with anembodiment.

FIG. 3 is a side view of layers of material that may be incorporatedinto a fabric item in accordance with an embodiment.

FIG. 4 is a cross-sectional side view of an illustrative electricalcomponent in accordance with an embodiment.

FIG. 5 is a cross-sectional side view of an illustrative electricalcomponent having an electrical device mounted on an interposer inaccordance with an embodiment.

FIG. 6 is a cross-sectional side view of an illustrative electricalcomponent having multiple electrical devices mounted on an interposer inaccordance with an embodiment.

FIG. 7 is a perspective view of an illustrative electrical componentmounted to conductive strands in accordance with an embodiment.

FIG. 8 is a perspective view of an illustrative electrical componenthaving an interposer with recesses for receiving conductive strands inaccordance with an embodiment.

FIG. 9 is a side view of an illustrative interposer with recesses thatare lined with conductive material in accordance with an embodiment.

FIG. 10 is a side view of an illustrative interposer with recesses thatare partially lined with conductive material in accordance with anembodiment.

FIG. 11 is a side view of an illustrative interposer with recesses thatare partially lined with conductive material in accordance with anembodiment.

FIG. 12 is a side view of a panel of multiple interposers prior to beingsingulated into individual interposers in accordance with an embodiment.

FIG. 13 is a side view of the interposers of FIG. 12 after beingsingulated into individual interposers in accordance with an embodiment.

FIG. 14 is a perspective view of an illustrative interposer havingnotches for receiving conductive strands on first and second opposingsides of the interposer in accordance with an embodiment.

FIG. 15 is a perspective view of an illustrative interposer havingnotches for receiving conductive strands on four sides of the interposerin accordance with an embodiment.

FIG. 16 is a perspective view of an illustrative interposer havingmultiple notches in each side of the interposer in accordance with anembodiment.

FIG. 17 is a perspective view an illustrative interposer having notchesfor receiving conductive strands that are cut to form two separatesignal paths in accordance with an embodiment.

FIG. 18 is a perspective view of an illustrative interposer havingnotches at the corners of the interposer in accordance with anembodiment.

FIG. 19 is a top view of an illustrative interposer that is rotatedrelative to conductive strands in accordance with an embodiment.

FIG. 20 is a top view of an illustrative interposer that is rotatedrelative to conductive strands and that is trimmed to fit in a pocket inaccordance with an embodiment.

FIG. 21 is a side view of an illustrative interposer having recesses ina lower surface that are partially enclosed to contain strands in therecesses in accordance with an embodiment.

FIG. 22 is a side view of an illustrative component having a protectivecover with trenches through which fabric strands are threaded inaccordance with an embodiment.

FIG. 23 is a bottom view of an illustrative component having aprotective cover with trenches through which fabric strands are threadedin accordance with an embodiment.

FIG. 24 is a side view of an illustrative component having a protectivecover with trenches through which fabric strands are threaded andopenings for exposing electrical devices on an interposer in accordancewith an embodiment.

FIG. 25 is a side view of an illustrative component having upper andlower protective covers that protrude beyond the edges of an interposerto form a trench through which fabric stands are threaded in accordancewith an embodiment.

FIGS. 26, 27, and 28 show illustrative steps involved in attaching acomponent to fabric strands using trenches in a protective cover and athermoplastic structure that guides the fabric strands into the trenchesin accordance with an embodiment.

FIGS. 29, 30, 31, 32, and 33 show illustrative steps involved inattaching a component to fabric strands by threading the fabric strandsthrough trenches in a protective cover and heating solder andthermoplastic material to draw the fabric strands down into the solderand under the thermoplastic material in accordance with an embodiment.

FIG. 34 is a side view of illustrative equipment including inductiveheating equipment and a transducer which may be used to attach acomponent to fabric in accordance with an embodiment.

FIG. 35 is a side view of an illustrative component in which athermoplastic structure presses fabric strands into trenches and issubsequently heated to seal the fabric strands in the trenches inaccordance with an embodiment.

FIG. 36 is a side view of an illustrative component in whichthermoplastic material has localized peaks around each trench to helpprevent fabric strands from escaping the trenches during the attachmentprocess in accordance with an embodiment.

FIG. 37 is a side view of an illustrative component in which trenches ina protective cover have straight sidewalls in accordance with anembodiment.

FIG. 38 is a side view of an illustrative component in which trenches ina protective cover have sloped sidewalls with a larger width at the topof the trench than at the bottom of the trench in accordance with anembodiment.

FIG. 39 is a side view of an illustrative component in which trenches ina protective cover have sloped sidewalls with a smaller width at the topof the trench than at the bottom of the trench in accordance with anembodiment.

FIG. 40 is a side view of an illustrative component in which solderhooks promote coupling between the fabric strands and the solder inaccordance with an embodiment.

FIG. 41 is a bottom view of an illustrative component in which trenchesin a protective cover have uniform width across the protective cover inaccordance with an embodiment.

FIG. 42 is a bottom view of an illustrative component in which trenchesin a protective cover have locally widened portions that are staggeredrelative to one another to accommodate larger pads in accordance with anembodiment.

FIG. 43 is a bottom view of an illustrative component in which trenchesin a protective cover have locally widened portions at the outer edgesof the protective cover to accommodate bends in fabric strands inaccordance with an embodiment.

DETAILED DESCRIPTION

Items such as item 10 of FIG. 1 may include fabric and may sometimes bereferred to as a fabric item or fabric-based item. Item 10 may be anelectronic device or an accessory for an electronic device such as alaptop computer, a computer monitor containing an embedded computer, atablet computer, a cellular telephone, a media player, or other handheldor portable electronic device, a smaller device such as a wrist-watchdevice, a pendant device, a headphone or earpiece device, a deviceembedded in eyeglasses or other equipment worn on a user's head, orother wearable or miniature device, a television, a computer displaythat does not contain an embedded computer, a gaming device, anavigation device, an embedded system such as a system in which fabricitem 10 is mounted in a kiosk, in an automobile, airplane, or othervehicle (e.g., an autonomous or non-autonomous vehicle), otherelectronic equipment, or equipment that implements the functionality oftwo or more of these devices. If desired, item 10 may be a removableexternal case for electronic equipment, may be a strap, may be a wristband or head band, may be a removable cover for a device, may be a caseor bag that has straps or that has other structures to receive and carryelectronic equipment and other items, may be a necklace or arm band, maybe a wallet, sleeve, pocket, or other structure into which electronicequipment or other items may be inserted, may be part of a chair, sofa,or other seating (e.g., cushions or other seating structures), may bepart of an item of clothing or other wearable item (e.g., a hat, belt,wrist band, headband, etc.), or may be any other suitable item thatincorporates fabric.

Item 10 may include intertwined strands of material such asmonofilaments and yarns that form fabric 12. Fabric 12 may form all orpart of a housing wall or other layer in an electronic device, may forminternal structures in an electronic device, or may form otherfabric-based structures. Item 10 may be soft (e.g., item 10 may have afabric surface that yields to a light touch), may have a rigid feel(e.g., the surface of item 10 may be formed from a stiff fabric), may becoarse, may be smooth, may have ribs or other patterned textures, and/ormay be formed as part of a device that has portions formed fromnon-fabric structures of plastic, metal, glass, crystalline materials,ceramics, or other materials.

The strands of material in fabric 12 may be single-filament strands(sometimes referred to as fibers) or may be yarns or other strands thathave been formed by intertwining multiple filaments of materialtogether. Examples of fabric 12 formed from yarn are sometimes describedherein as an example. This is, however, merely illustrative. Yarn-basedfabric for item 10 may, if desired, be partly or completely formed frommonofilaments.

The yarns in fabric 12 may be formed from polymer, metal, glass,graphite, ceramic, natural materials as cotton or bamboo, or otherorganic and/or inorganic materials and combinations of these materials.Conductive coatings such as metal coatings may be formed onnon-conductive material. For example, plastic yarns and monofilaments infabric 12 may be coated with metal to make them conductive. Reflectivecoatings such as metal coatings may be applied to make yarns andmonofilaments reflective. Yarns may be formed from a bundle of baremetal wires or metal wire intertwined with insulating monofilaments (asexamples).

Yarn may be intertwined to form fabric 12 using intertwining equipmentsuch as weaving equipment, knitting equipment, or braiding equipment.Intertwined yarn may, for example, form woven fabric. Conductive yarnand insulating yarn may be woven, knit, braided, or otherwiseintertwined to form contact pads that can be electrically coupled toconductive structures in item 10 such as the contact pads of anelectrical component.

Conductive yarn and insulating yarn may also be woven, knit, orotherwise intertwined to form conductive paths. The conductive paths maybe used in forming signal paths (e.g., signal buses, power lines forcarrying power, etc.), may be used in forming part of a capacitive touchsensor electrode, a resistive touch sensor electrode, or otherinput-output device, or may be used in forming other patternedconductive structures. Conductive structures in fabric 12 may be used incarrying electrical current such as power, digital signals, analogsignals, sensor signals, control signals, data, input signals, outputsignals, or other suitable electrical signals.

Item 10 may include additional mechanical structures 14 such as polymerbinder to hold yarns in fabric 12 together, support structures such asframe members, housing structures (e.g., an electronic device housing),and other mechanical structures.

To enhance mechanical robustness and electrical conductivity atyarn-to-yarn connections, additional structures and materials (e.g.,solder, crimped metal connections, welds, conductive adhesive such asanisotropic conductive film and other conductive adhesive,non-conductive adhesive, fasteners, etc.) may be used to help formyarn-to-yarn connections. These yarn-to-yarn connections may be formedwhere yarns cross each other perpendicularly or at other yarnintersections where connections are desired. Insulating material can beinterposed between intersecting conductive yarns at locations in whichit is not desired to form a yarn-to-yarn connection. The insulatingmaterial may be plastic or other dielectric, may include an insulatingyarn or a conductive yarn with an insulating coating or insulatedconductive monofilaments, etc. Solder connections may be formed betweenconductive yarns by melting solder so that the solder flows overconductive yarns. The solder may be melted using an inductive solderinghead to heat the solder, using a reflow oven to heat the solder, using alaser or hot bar to heat the solder, or using other soldering equipment.During soldering, outer dielectric coating layers (e.g., outer polymerlayers) may be melted away in the presence of molten solder, therebyallowing underlying metal yarns to be soldered together.

Circuitry 16 may be included in item 10. Circuitry 16 may includeelectrical components that are coupled to fabric 12, electricalcomponents that are housed within an enclosure formed by fabric 12,electrical components that are attached to fabric 12 using welds, solderjoints, adhesive bonds (e.g., conductive adhesive bonds such asanisotropic conductive adhesive bonds or other conductive adhesivebonds), crimped connections, or other electrical and/or mechanicalbonds. Circuitry 16 may include metal structures for carrying current,electrical components such as integrated circuits, light-emittingdiodes, sensors, and other electrical devices. Control circuitry incircuitry 16 may be used to control the operation of item 10 and/or tosupport communications with item 18 and/or other devices.

Item 10 may interact with electronic equipment or other additional items18. Items 18 may be attached to item 10 or item 10 and item 18 may beseparate items that are configured to operate with each other (e.g.,when one item is a case and the other is a device that fits within thecase, etc.). Circuitry 16 may include antennas and other structures forsupporting wireless communications with item 18. Item 18 may alsointeract with item 10 using a wired communications link or otherconnection that allows information to be exchanged.

In some situations, item 18 may be an electronic device such as acellular telephone, computer, or other portable electronic device anditem 10 may form a cover, case, bag, or other structure that receivesthe electronic device in a pocket, an interior cavity, or other portionof item 10. In other situations, item 18 may be a wrist-watch device orother electronic device and item 10 may be a strap or other fabric itemthat is attached to item 18 (e.g., item 10 and item 18 may together forma fabric-based item such as a wristwatch with a strap). In still othersituations, item 10 may be an electronic device, fabric 12 may be usedin forming the electronic device, and additional items 18 may includeaccessories or other devices that interact with item 10. Signal pathsformed from conductive yarns and monofilaments may be used to routesignals in item 10 and/or item(s) 18.

The fabric that makes up item 10 may be formed from yarns and/ormonofilaments that are intertwined using any suitable intertwiningequipment. With one suitable arrangement, which may sometimes bedescribed herein as an example, fabric 12 may be woven fabric formedusing a weaving machine. In this type of illustrative configuration,fabric may have a plain weave, a basket weave, a satin weave, a twillweave, or variations of these weaves, may be a three-dimensional wovenfabric, or may be other suitable fabric.

A cross-sectional side view of illustrative woven fabric 12 is shown inFIG. 2. As shown in FIG. 2, fabric 12 may include yarns or other strandsof material 80. Strands 80 may include warp strands 20 and weft strands22. If desired, additional strands that are neither warp nor weftstrands may be incorporated into fabric 12. The example of FIG. 2 ismerely illustrative. In the illustrative configuration of FIG. 2, fabric12 has a single layer of woven strands 80. Multi-layer fabricconstructions may be used for fabric 12 if desired.

Item 10 may include non-fabric materials (e.g., structures formed fromplastic, metal, glass, ceramic, crystalline materials such as sapphire,etc.). These materials may be formed using molding operations,extrusion, machining, laser processing, and other fabricationtechniques. In some configurations, some or all of item 10 may includeone or more layers of material such as layers 24 of FIG. 3. Layers 24may include layers of polymer, metal, glass, fabric, adhesive,crystalline materials, ceramic, substrates on which components have beenmounted, patterned layers of material, layers of material containingpatterned metal traces, thin-film devices such as transistors, and/orother layers.

A side view of an illustrative electrical component of the type that maybe used in item 10 is shown in FIG. 4. Electrical components in item 10such as illustrative electrical component 26 of FIG. 4 may includediscrete electrical components such as resistors, capacitors, andinductors, may include connectors, may include batteries, may includeinput-output devices such as switches, buttons, light-emittingcomponents such as light-emitting diodes, audio components such asmicrophones and speakers, vibrators (e.g., piezoelectric actuators thatcan vibrate), solenoids, electromechanical actuators, motors, and otherelectromechanical devices, microelectromechanical systems (MEMs)devices, pressure sensors, light detectors, proximity sensors(light-based proximity sensors, capacitive proximity sensors, etc.),force sensors (e.g., piezoelectric force sensors), strain gauges,moisture sensors, temperature sensors, accelerometers, gyroscopes,compasses, magnetic sensors (e.g., Hall effect sensors andmagnetoresistance sensors such as giant magnetoresistance sensors),touch sensors, and other sensors, components that form displays, touchsensors arrays (e.g., arrays of capacitive touch sensor electrodes toform a touch sensor that detects touch events in two dimensions), andother input-output devices, electrical components that form controlcircuitry such as non-volatile and volatile memory, microprocessors,application-specific integrated circuits, system-on-chip devices,baseband processors, wired and wireless communications circuitry, andother integrated circuits.

Electrical components such as component 26 may be bare semiconductordies (e.g., laser dies, light-emitting diode dies, integrated circuits,etc.) or packaged components (e.g. semiconductor dies or other devicespackaged within plastic packages, ceramic packages, or other packagingstructures). One or more electrical terminals such as contact pads 30may be formed on body 28 of component 26. Body 28 may be a semiconductordie (e.g., a laser die, light-emitting diode die, integrated circuit,etc.) or may be a package for a component (e.g., a plastic package orother dielectric package that contains one or more semiconductor dies orother electrical devices). Contacts for body 28 such as pads 30 may beprotruding leads, may be planar contacts, may be formed in an array, maybe formed on any suitable surfaces of body 28, or may be any othersuitable contacts for forming electrical connections to component 26.For example, pads 30 may be metal solder pads.

As shown in the example of FIG. 5, body 28 may be mounted on a supportstructure such as interposer 36. Interposer 36 may be a printed circuit,ceramic carrier, or other dielectric substrate. Interposer 36 may belarger than body 28 or may have other suitable sizes. Interposer 36 mayhave a planar shape with a thickness of 700 microns, more than 500microns, less than 500 microns, or other suitable thickness. Thethickness of body 28 may be 500 microns, more than 300 microns, lessthan 1000 microns, or other suitable thickness. The footprint (areaviewed from above) of body 28 and interposer 36 may be 10 microns×10microns, 100 microns×100 microns, more than 1 mm×1 mm, less than 10mm×10 mm, may be rectangular, may be square, may have L-shapes, or mayhave other suitable shapes and sizes.

Interposer 36 may contain signal paths such as metal traces 38. Metaltraces 38 may have portions forming contacts such as pads 34 and 40.Pads 34 and 40 may be formed on the upper surface of interposer 36, onthe lower surface of interposer 36, or on the sides of interposer 36.Conductive material such as conductive material 32 may be used inmounting body 28 to interposer 36. Conductive material 32 may be solder(e.g., low temperature or high temperature solder), may be conductiveadhesive (isotropic conductive adhesive or anisotropic conductive film),may be formed during welding, or may be other conductive material forcoupling electrical device pads (body pads) such as pads 30 on body 28to interposer pads 34. Metal traces 38 in interposer 36 may couple pads34 to other pads such as pads 40. If desired, pads 40 may be largerand/or more widely spaced than pads 34, thereby facilitating attachmentof interposer 36 to conductive yarns and/or other conductive paths initem 10. Solder, conductive adhesive, or other conductive connectionsmay be used in coupling pads 40 to conductive yarn, conductivemonofilament, printed circuit traces, or other conductive path materialsin item 10.

FIG. 6 shows an example in which component 26 includes a protectivestructure such as protective structure 130 on interposer 36. Protectivestructure 130 may, for example, be a plastic structure that completelyor partially encapsulates devices 28 and interposer 36 to providemechanical robustness, protection from moisture and other environmentalcontaminants, heat sinking, and/or electrical insulation. Protectivestructure 130 may be formed from molded plastic (e.g., injection-moldedplastic, transfer molded plastic, low-pressure molded plastic, two-partmolded plastic, etc.) that has been molded over devices 28 andinterposer 36 or that is pre-formed into the desired shape andsubsequently attached to interposer 36, may be a layer of polymer suchas polyimide that has been cut or machined into the desired shape andsubsequently attached to interposer 36, or may be formed using othersuitable methods. Illustrative materials that may be used to formprotective structure 130 include epoxy, polyamide, polyurethane,silicone, other suitable materials, or a combination of any two or moreof these materials. Protective structure 130 may be formed on one orboth sides of interposer 36 (e.g., may completely or partially surroundinterposer 36).

Protective structure 130 may be entirely opaque, may be entirelytransparent, or may have both opaque and transparent regions.Transparent portions of protective structure 130 may allow light emittedfrom one or more devices 28 to be transmitted through protectivestructure 130 and/or may allow external light to reach (and be detectedby) one or more devices 28. Protective cover 130 may, if desired, havedifferent thicknesses. The example of FIG. 6 in which protective cover130 has uniform thickness across interposer 36 is merely illustrative.

If desired, interposer 36 may be sufficiently large to accommodatemultiple electrical devices each with a respective body 28. For example,multiple light-emitting diodes, sensors, and/or other electrical devicesmay be mounted to a common interposer such as interposer 36 of FIG. 6.The light-emitting diodes may be micro-light-emitting diodes (e.g.,light-emitting diode semiconductor dies having footprints of about 10microns×10 microns, more than 5 microns×5 microns, less than 100microns×100 microns, or other suitable sizes). The light-emitting diodesmay include light-emitting diodes of different colors (e.g., red, green,blue, white, etc.), infrared light, or ultraviolet light. Redundantlight-emitting diodes or other redundant circuitry may be included oninterposer 36. In configurations of the type shown in FIG. 6 in whichmultiple electrical devices (each with a respective body 28) are mountedon a common interposer, electrical component 26 may include any suitablecombination of electrical devices (e.g., light-emitting diodes, sensors,integrated circuits, actuators, and/or other devices of the typedescribed in connection with electrical component 26 of FIG. 4).

The examples of FIGS. 5 and 6 in which devices 28 are only located onone side of interposer 36 are merely illustrative. If desired, devices28 may be mounted to both sides of interposer 36.

Electrical components may be coupled to fabric structures, individualyarns or monofilaments, printed circuits (e.g., rigid printed circuitsformed from fiberglass-filled epoxy or other rigid printed circuit boardmaterial or flexible printed circuits formed from polyimide substratelayers or other sheets of flexible polymer materials), metal or plasticparts with signal traces, or other structures in item 10.

In some configurations, item 10 may include electrical connectionsbetween components 26 and conductive paths in fabric 12. Fabric 12 mayinclude strands 80 (e.g., conductive yarns and/or conductivemonofilaments) for carrying electrical current (e.g., power, digitalsignals, analog signals, sensor signals, control signals, data, inputsignals, output signals, or other suitable electrical signals) to and/orfrom components 26. The strands may be used to form fabric contact pads.Consider, as an example, fabric 12 of FIG. 7. As shown in FIG. 7, fabric12 may contain strands 80. Strands 80 may be warp strands, weft strands,or other suitable strands in fabric 12. One or more of strands 80 may beconductive and may form a contact pad. Component 26 may have contactpads such as pad 40. Solder or other conductive material 82 may be usedto couple pads 40 to the pads formed by strands 80. In the example ofFIG. 7, pads 40 are formed on a lower surface of interposer 36 (e.g., asurface that is opposite the surface on which component 28 is mounted).Conductive material 82 may be used to electrically and mechanicallycouple component 26 to strands 80 of fabric 12.

In the example of FIG. 7, pads 40 are formed from elongated strips ofconductive material (e.g., metal) that extend from one edge ofinterposer 36 to an opposing edge of interposer 36. This provides alarge area with which to form a mechanical and electrical connectionbetween interposer 36 and strands 80. As shown in FIG. 7, each strand 80extends parallel to one of pads 40. The elongated shape of pads 40allows conductive material 82 to attach a longer portion of strand 80 topad 40. The connection between pad 40 and strand 80 may, for example,span across the width of interposer 36, thereby providing a robustconnection between interposer 36 and strand 80.

In some configurations, it may be desirable to provide a more robustmechanical connection between component 26 (e.g., component 26 of FIGS.4, 5, and 6) and fabric 12 to ensure that component 26 does not comeloose when fabric 12 is bent or stretched. To increase the robustness ofthe connection between strands 80 and component 26, component 26 mayhave one or more recesses for receiving strands 80. For example, strands80 may each be “threaded” through a portion of component 26 to helpsecure component 26 to fabric 12. Strands 80 may be threaded throughportions (e.g., recesses, openings, trenches, etc.) of device 28,interposer 36, protective structure 130, and/or other portions ofcomponent 26. FIGS. 8-21 illustrate examples in which strands 80 arethreaded through portions of interposer 36. FIGS. 22-43 illustrateexamples in which strands 80 are threaded through portions of protectivestructure 130. It should be understood, however, that the geometries ofinterposer 36 (e.g., the location, shape, and size of recesses ininterposer 36) and other features of FIGS. 8-21 may be applied toprotective structure 130, and that the geometries of protectivestructure 130 (e.g., the location, shape, and size of recesses inprotective structure 130) and other features of FIGS. 22-43 may beapplied to interposer 36. In general, component 26 may have anycombination of features shown in FIGS. 8-43.

As shown in FIG. 8, interposer 36 may have multiple layers such aslayers 42.

Interposer 36 may, for example, be a multi-layer printed circuit. Layers42 may include flexible printed circuit layers, rigid printed circuitlayers, or a combination of rigid and flexible printed circuit layers.Layers 42 of interposer 36 may include dielectric materials such asfiberglass-filled epoxy (e.g., as a rigid layer), polyimide (e.g., as aflexible layer), FR-2 (phenolic cotton paper), FR-3 (cotton paper andepoxy), FR-4 (woven glass and epoxy), FR-5 (woven glass and epoxy), FR-6(matte glass and polyester), G-10 (woven glass and epoxy), CEM-1 (cottonpaper and epoxy), CEM-2 (cotton paper and epoxy), CEM-3 (woven glass andepoxy), CEM-4 (woven glass and epoxy), CEM-5 (woven glass andpolyester), paper impregnated with phenolic resin, polystyrene,polyimide, polytetrafluoroethylene (PTFE), plastic, other polymers,ceramics, or other suitable dielectrics. Layers 42 may includeattachment layers such as layers of prepreg (e.g., pre-impregnatedlayers of fiber and resin).

Layers 42 may contain metal traces (sometimes referred to asinterconnects). The metal traces may include patterned signal lines andvias for routing signals between components that are mounted oninterposer 36. The metal traces may include ground plane structures(e.g., blanket sections of metal traces that serve as ground). There maybe any suitable number of metal layers in layers 42. For example, layers42 may contain two layers of metal, three layers of metal, four layersof metal, more than four layers of metal, or fewer than four layers ofmetal. Metal layers in layers 42 may be formed from copper, silver,tungsten, other suitable metals, or a combination of any two or more ofthese metals.

As shown in FIG. 8, interposer 36 includes first layer 42-1, secondlayer 42-2 (sometimes referred to as a spacer layer), and third layer42-3. In one illustrative arrangement, first layer 42-1 and third layer42-3 are flexible printed circuits and second layer 42-2 is a rigidprinted circuit. This is, however, merely illustrative. If desired,layers 42-1 and 42-3 may be rigid printed circuits and layer 42-2 may bea flexible printed circuit, all three layers may be flexible printedcircuits, all three layers may be rigid printed circuits, or layers 42may include any other suitable combination of rigid and flexible layers.Arrangements where upper layer 42-1 and lower layer 42-3 are flexibleprinted circuits and layer 42-2 is a rigid printed circuit are sometimesdescribed herein as an illustrative example. In still otherarrangements, one or more of layers 42 may not contain any circuitry.For example, layer 42-2 and layer 42-3 may be structural support layersthat do not include any circuitry, if desired.

The example of FIG. 8 in which interposer 36 includes three printedcircuit substrates 42-1, 42-2, and 42-3 is merely illustrative. Ifdesired, interposer may include four printed circuit substrates, fiveprinted circuit substrate, six or more printed circuit substrates, orless than three printed circuit substrates.

If desired, components may be mounted to one or both of the opposingsurfaces of interposer 36. In the example of FIG. 8, one or morecomponents such as component 28-1 is mounted to the upper surface ofinterposer 36 (e.g., the surface formed by upper layer 42-1) and one ormore components such as component 28-2 is mounted to the opposing lowersurface of interposer 36 (e.g., the surface formed by lower layer 42-3).

Interposer 36 may include recesses such as recesses 50. In the exampleof FIG. 8, interposer 36 includes a first recess 50 on one side ofinterposer 36 and a second recess 50 on an opposing side of interposer36. Recesses 50 are formed where upper and lower layers 42-1 and 42-3extend beyond the outer edge of middle layer 42-2. In other words,recesses 50 are formed where middle layer 42-2 is recessed relative toupper and lower layers 42-1 and 42-3, thereby forming a gap betweenupper layer 42-1 and lower layer 42-3. The open space between upper andlower layers 42-1 and 42-3 at the edges of interposer 36 creates acavity for receiving one of strands 80 of fabric 12. As shown in FIG. 8,each strand 80 passes through a respective one of recesses 50.

In the example of FIG. 8, recesses 50 (sometimes referred to as groovesor cavities) extend parallel to one another along the y-axis of FIG. 8.This allows recesses 50 to receive strands 80 that also extend along they-axis of FIG. 8. This is, however, merely illustrative. If desired,recesses 50 may extend parallel to the x-axis of FIG. 8 so that recesses50 receive strands 80 that extend along the x-axis. Recesses 50 thatextend parallel to the x-axis may be used in place of recesses 50 ofFIG. 8 or may be used in conjunction with recesses 50 of FIG. 8.Interposer 36 may have two recesses 50 for receiving two strands 80, mayhave four recesses 50 for receiving four strands 80 (e.g., two warpstrands and two weft strands), may have only one recess 50 for receivingone strand, may have six recesses 50 for receiving six strands, may havemore than six recesses 50, less than six recesses 50, etc.).Arrangements where interposer 36 includes additional layers 42 may allowfor additional recesses 50 in interposer 36. For example, interposer 36may have two additional layers 42 between layer 42-3 and component 28-2.One of the additional layers may be recessed relative to the twoadjacent layers, thereby forming additional recesses 50 for receivingstrands 80.

Strands 80 may be electrically and mechanically coupled to conductivepads in recesses 50 of interposer 36. FIGS. 9, 10, and 11 showillustrative examples of conductive pads that may be formed in recesses50.

In the example of FIG. 9, conductive pads 40 fully line the surfacesthat form recesses 50. A portion of lower surface 44 of layer 42-1, aportion of upper surface 46 of layer 42-3 and edge surface 48 of layer42-2 are covered with a conductive material to form pad 40. Conductivematerial (e.g., conductive material 82 of FIG. 7) may be used toelectrically couple conductive portions of strands 80 to pads 40 ofinterposer 36.

In the example of FIG. 10, conductive pads 40 partially line thesurfaces that form recesses 50. A portion of lower surface 44 of layer42-1 and a portion of upper surface 46 of layer 42-3 are covered with aconductive material to form bond pads 40 in recesses 50.

In the example of FIG. 11, only the peripheral edge surface of middlelayer 42-2 is covered with conductive material to form bond pads 40 inrecesses 50.

Pads 40 may be formed by plating techniques or other suitable metaldeposition techniques. In configurations where solder is used toelectrically couple strands 80 to pads 40, inductive solderingtechniques or other soldering techniques (e.g., techniques involvingapplication of heat to solder using a hot bar or reflow oven), may beused to melt solder and thereby cause molten solder to penetrate intorecess 50. Conductive strands 80 that are soldered to pads 40 inrecesses 50 may be resistant to becoming dislodged due to the enhancedengagement between strands 80 and interposer 36.

Signals may be conveyed between electrical devices 28 and conductivestrands 80 using metal traces 38. For example, layer 42-1 may includemetal traces 38-1, layer 42-2 may include metal traces 38-2, and layer42-3 may include metal traces 38-3 for conveying signals between thepads on interposer 36 coupled to device 28 (e.g., pads 34 of FIG. 5) andthe pads on interposer 36 coupled to strand 80 (e.g., pads 40 of FIGS.9, 10, and 11).

FIGS. 12 and 13 show an illustrative method for forming recesses of thetype shown in FIG. 8. As shown in FIG. 12, interposers 36 may be formedfrom a panel such as panel 86 that includes multiple interposers 36. Atleast some of layers 42 in panel 86 may be separated from one anotherusing a solder bar such as solder bar 54. In the example of FIG. 12,layers 42-1 and 42-3 are continuous across the multiple interposers 36in panel 86. Layer 42-2, on the other hand, is broken up into portionsthat are separated from one another by solder bar 54. Solder bar 54 may,for example, be a flux-core solder bar or other suitable soldermaterial. Solder bar 54 may be electrically connected to conductive padson each interposer 36 (e.g., conductive pads 40 of the type shown inFIGS. 9, 10, and 11).

A laser, saw, or other cutting tool may be used to singulate interposers36. For example, a laser cutting tool such as laser 88 may be used toemit laser light in direction 90 to cut through panel 86 and therebyseparate panel 86 into individual interposers 36, as shown in FIG. 13.The laser light emitted by laser 88 during the singulation process mayheat and melt solder bar 54 so that cavities 50 are formed between upperlayer 42-1 and lower layer 42-3 of each interposer 36. Strands 80 may bethreaded through recesses 50 and solder 54 may be melted to lock strandsin place in recesses 50 of interposers 36. If desired, additionalconductive material or other structures may be formed on the outside ofthe conductive strand so that the conductive strand is fully enclosedwithin recess 50. If desired, other methods of forming recesses 50 maybe used. The method of FIGS. 12 and 13 is merely illustrative.

FIG. 14 illustrates another way of engaging interposer 36 with strands80 of fabric 12. Interposer 36 of FIG. 14 may be a single layerinterposer of the type shown in FIG. 7, may be a multi-layer interposerof the type shown in FIG. 8, or may have other suitable construction. Asshown in FIG. 14, interposer 36 has notches such as notches 56 onopposing sides of interposer 36. Notches 56 extend from upper surface 92of interposer 36 to lower surface 94 of interposer 36 (e.g., parallel tothe z-axis of FIG. 14).

Notches 56 (sometimes referred to as recesses, openings, cavities,slots, holes, or castellations) may each be configured to receive anassociated one of strands 80 of fabric 12. As shown in FIG. 14, eachstrand 80 may have a first portion such as portion 96 that passes overtop surface 92 of interposer 36, a second portion such as portion 98that passes over lower surface 94 of interposer 36, and a third portionsuch as portion 100 that passes through notch 56 (e.g., from uppersurface 92 to lower surface 94 or vice versa). In other words, strands80 may be “threaded” through notches 56 to enhance the mechanicalengagement between strands 80 and interposer 36.

Notches 56 may be lined or partially lined with conductive material 40that forms bond pads in notches 56. Solder or other conductive materialmay be used to electrically and mechanically couple strands 80 toconductive pads 40 in notches 56 of interposer 36. Pads 40 may be formedby plating techniques or other suitable metal deposition techniques. Inconfigurations where solder is used to electrically couple strands 80 topads 40, inductive soldering techniques or other soldering techniques(e.g., techniques involving application of heat to solder using a hotbar or reflow oven), may be used to melt solder and thereby cause moltensolder to penetrate into notch 56. Conductive strands 80 that aresoldered to pads 40 in notches 56 may be resistant to becoming dislodgeddue to the enhanced engagement between strands 80 and interposer 36.

The example of FIG. 14 in which notches 56 are formed on first andsecond opposing sides of interposer 36 is merely illustrative. Ifdesired, notches 56 may be formed on one side, two sides, three sides,or all four sides of interposer 36. In configurations where interposer36 has multiple layers (e.g., layers 42 of FIG. 8), each notch 56 mayextend through all of the layers or may extend through less than all ofthe layers.

FIG. 15 shows an example in which notches 56 have been formed on allfour sides of interposer 36. As in the example of FIG. 14, each strand80 may have a first portion such as portion 96 that passes over topsurface 92 of interposer 36, a second portion such as portion 98 thatpasses over lower surface 94 of interposer 36, and a third portion suchas portion 100 that passes through notch 56 (e.g., from upper surface 92to lower surface 94 or vice versa). In other words, strands 80 may be“threaded” through notches 56 to enhance the mechanical engagementbetween strands 80 and interposer 36. The arrangement of FIG. 15 allowsboth warp strands and weft strands to be threaded through interposer 36.For example, strands 80 extending parallel to the x-axis of FIG. 15 maybe weft strands and strands 80 extending parallel to the y-axis of FIG.15 may be warp strands, or vice versa.

FIG. 16 shows an example in which multiple notches 56 have been formedon each of the four sides of interposer 36. In this example, each strand80 extending parallel to the x-axis of FIG. 16 has two portions 102 thatpass over lower surface 94 of interposer 36, two portions 106 that passthrough notches 56, and middle portion 104 that passes over uppersurface 92 of interposer 36 (between notches 56). Each strand 80extending parallel to the y-axis of FIG. 16 has two portions 108 thatpass over upper surface 92 of interposer 36, two portions 112 that passthrough notches 56, and middle portion 110 that passes over lowersurface 94 of interposer 36 (between notches 56).

FIG. 17 shows an example in which one or more of strands 80 have beencut to form first and second distinct signal paths from the same strand.Interposer 36 may have the same configuration as interposer 36 of FIG.16 or may have any other suitable configuration. Components oninterposer 36 such as components 28 may have multiple terminals (e.g.,two or more terminals, three or more terminals, four or more terminals,or other suitable number of terminals). It may be desirable to couplethese terminals to a single strand while still using separate signalpaths for each terminal. As shown in FIG. 17, portion 104 of strand 80may be cut to form a gap 60 that separates strand 80 into first strandsegment 80A and second strand segment 80B. Strand segment 80A has afirst end such as end 64A coupled to conductive pad 40A in notch 56A andstrand segment 80B has a second end such as end 64B coupled toconductive pad 40B in notch 56B. A component mounted to interposer 36may have a first terminal coupled to pad 40A and a second terminalcoupled to pad 40B. The first terminal of the component may beelectrically coupled to strand segment 80A, whereas the second terminalof the component may be electrically coupled to strand segment 80B.

The example of FIG. 17 in which both of the strands 80 extendingparallel to the x-axis of FIG. 17 are cut to form two separate signalpaths is merely illustrative. If desired, only one of these two strandsmay be cut and the other may form a continuous path. If desired, one ormore of strands 80 that extend parallel to the y-axis of FIG. 17 may becut to form two strand segments and separate signal paths.

FIG. 18 shows an example in which notches 56 are formed on opposingsides of each corner of interposer 36. Strands 80 that extend parallelto the x-axis of FIG. 18 may have a portion such as portion 114 thatextends over lower surface 94 of interposer 36. On either side ofportion 114, strand 80 has portions 116 that extend through notches 56on opposing sides of interposer 36. Strands 80 that extend parallel tothe y-axis of FIG. 18 may have a portion such as portion 118 thatextends over upper surface 92 of interposer 36. On either side ofportion 118, strand 80 has portions 120 that extend through notches 56on opposing sides of interposer 36. If desired, one or more of strands80 may be cut (e.g., as in the example of FIG. 17) to form separatesignal paths from a single strand 80.

If desired, strands 80 may be mechanically coupled to interposer 36 inadditional locations (e.g., locations other than notches 56). Forexample, adhesive, solder, or other suitable attachment members may beused to attach strands 80 to upper surface 92 and/or lower surface 94 ofinterposer 36 (e.g., as in the example of FIG. 7). Using notchconnections in conjunction with upper/lower surface connections may helpsecurely attach interposer 36 to fabric 12. In this type of arrangement,some of the connections may be purely mechanical and need not beelectrical. For example, upper/lower surface connections of the typeshown in FIG. 7 may be purely mechanical connections and notchconnections of the type shown in FIGS. 14-18 may be electrical andmechanical connections, or vice versa.

If desired, recesses of the type shown in FIG. 8 and notches of the typeshown in FIGS. 14-18 may be modified to fully surround conductive strand70. For example, rather than a recess or notch that exposes strand 80 onone side, recesses 50 and notches 56 may be holes in interposer 36 thatare completely surrounded by portions of interposer 36. In other words,rather than removing an outermost edge portion of interposer 36 to formnotch 56, a fully enclosed hole may be formed in interposer 36 slightlyoffset from the edge of interposer 36. Holes of this type in interposer36 may ensure that component 26 remains on fabric 12 even if a solderconnection between interposer 36 and strand 80 fails.

In the examples of FIGS. 7, 8, 14, 15, 16, 17, and 18, interposer 36 ismounted to fabric 12 such that some strands 80 of fabric 12 extendparallel to the sides of interposer 36 and some strands 80 of fabric 12extend perpendicular to the sides of interposer 36. This is merelyillustrative. If desired, interposer 36 may be mounted to fabric 12 suchthat the sides of interposer 36 are angled relative to strands 80 offabric 12 (e.g., oriented at an angle between 0° and 90°). This type ofarrangement is illustrated in FIGS. 19 and 20.

As shown in FIG. 19, interposer 36 may be mounted to strands 80 suchthat the sides of interposer 36 are angled relative to strands 80. Theangle ⊖ between side 124 and strand 80 may, for example, be between 0°and 90°, 0° and 45°, 45° and 90°, 30° and 60°, about 45°, or othersuitable angle.

Notches 56 may be located on opposing sides of one or more corners ofinterposer 36 such that each strand 80 extends through a notch 56 on oneside of interposer 36 (e.g., side 122) and through a notch 56 on anadjacent side of interposer 36 (e.g., side 124). The example of FIG. 19in which strands 80 extend over the same side of interposer 36 is merelyillustrative. If desired, one strand 80 may extend over the top ofinterposer 36 and another strand 80 may extend under the bottom ofinterposer 36. Notches 56 may be formed on either side of one corner, oneither side of two corners, on either side of three corners, or oneither side of all four corners of interposer 36.

In some arrangements, component 26 may be embedded in fabric 12 byinserting component 26 into a pocket formed in fabric 12. For example,during the process of weaving or otherwise forming fabric 12, a pocketmay be formed in fabric 12 that helps fabric 12 receive electricalcomponents 26 and that helps align the conductive pads of component 26with the conductive structures in fabric 12. Pockets in fabric 12 may beformed by omitting layers of fabric from internal portions of fabriclayer 12, thereby forming a pocket having a shape and size appropriateto receive component 26.

It may be desirable to alter the shape of interposer 36 to fit the shapeand size of the pocket in fabric 12. As shown in FIG. 20, for example,fabric 12 may have a pocket such as rectangular pocket 68. Pocket 68 maybe formed during weaving operations (or other fabric assemblyoperations) and component 26 may be mounted in pocket 68 during weavingoperations (or other fabric assembly operations). Pocket 68 may beformed by changing the architecture of the fabric using two or morelayers of fabric.

In the example of FIG. 20, pocket 68 forms a rectangular recess infabric 20 for receiving component 26. In order to fit the shape ofpocket 68, the corners of interposer 36 may be trimmed (e.g., squaredoff) such that the edges of interposer 36 do not extend beyond the wallsof pocket 68 in fabric 12. The example of FIG. 20 where all four cornershave been trimmed and to fit within pocket 68 is merely illustrative. Ifdesired, fewer than all four corners of interposer 36 may be trimmed toprovide interposer 36 with a desired shape based on the correspondingshape of pocket 68 in fabric 12. Arrangements where one or more sides ofinterposers 36 is trimmed to fit within pocket 68 may also be used.

FIG. 21 shows an example in which notches 56 have been formed in a lowersurface of interposer 36. Each strand 80 may pass through an associatedone of notches 56. In other words, strands 80 may be “threaded” throughnotches 56 to enhance the mechanical engagement between strands 80 andinterposer 36. If desired, a portion of interposer 36 such as portion130 may extend behind strand 80 such that strand 80 is partiallyenclosed by interposer 36 within notch 56 (e.g., such that interposer 36completely or partially surrounds the diameter of strand 80). Notches 56may be lined or partially lined with conductive material 40 that formsbond pads in notches 56. Solder or other conductive material may be usedto electrically and/or mechanically couple strands 80 to conductive pads40 in notches 56 of interposer 36.

FIGS. 22-43 illustrate examples in which strands 80 are threaded throughportions of protective structure 130 (e.g., in components of the typeshown in FIG. 6). In the example of FIG. 22, protective structure 130 isformed on opposing sides of interposer 36. Protective structure 130 mayinclude trenches such as trenches 134 (sometimes referred to asrecesses, openings, notches, grooves, etc.). Trenches 134 may be formedby removing portions of protective structure 130 (e.g., using a laser, amechanical saw, a mechanical mill, or other equipment) or may be formedby molding (e.g., injection molding) or otherwise forming protectivestructure 130 into a shape that includes trenches 134. Trenches may havea width between 2 mm and 6 mm, between 1 mm and 5 mm, between 3 mm and 8mm, greater than 3 mm, less than 3 mm, or other suitable width. Ifdesired, trenches 134 may have different depths (e.g., to expose contactpads 40 that are located at different z-heights of interposer 36).

Trenches 134 may expose conductive pads 40 on interposer 36. Strands 80may each be threaded through an associated one of trenches 134 inprotective structure 130. Solder or other conductive material 142 may beused to electrically and mechanically couple strands 80 to conductivepads 40 in notches 134 of protective cover 130. Because strands 80 arewedged between portions of protective cover 130, strands 80 may beresistant to becoming dislodged from interposer 36. In addition toholding strands 80 in place so that component 26 remains attached tofabric 12, trenches 134 may also be used as a physical guide foraligning component 26 relative to fabric 12 during the attachmentprocess. This may be beneficial when aligning and attaching component 26to fabric 12 without line of sight.

FIG. 23 is a bottom view of component 26 (e.g., component 26 of FIG. 22)showing how adhesive may, if desired, be used to enhance the mechanicalrobustness of the connection between component 26 and strands 80. Asshown in FIG. 23, adhesive 136 (e.g., a hot-melt adhesive, epoxy, athermoplastic material such as ethylene-vinyl acetate, acrylic,polyethylene, other thermoplastic material, or other suitable adhesive)may attach portions of strands 80 in trenches 134 to interposer 36. Ifdesired, adhesive 136 may be used to attach non-conductive portions ofstrands 80 to interposer 36, whereas conductive portions of strands 80may be attached to pads 40 using solder 142 (FIG. 22). This is, however,merely illustrative. If desired both solder and adhesive may be used toattach a given portion of strands 80 to interposer 36. Solder mayprovide electrical coupling while a hot-melt adhesive or other material(e.g., an encapsulant) may form a seal around the electrical connectionto protect the connection from mechanical damage as well as moisture andother environmental contaminants. If desired, a solder mask may be usedin regions of trenches 134 without pads 40 to help prevent solder 142from reaching those areas.

FIG. 24 shows an example in which devices 28, protective cover 130, andstrands 80 are all formed on one side of interposer 36. If desired,protective cover 130 may selectively expose one or more electricaldevices 28 on interposer 36. In the example of FIG. 24, top surface 138of device 28 is exposed through an opening in protective cover 130. Thismay allow an external electrical path (e.g., a flex circuit, aconductive strand, etc.) to couple to device 28 and/or may allow device28 to send or receive information without requiring that information topass through protective cover 130. For example, if device 28 is a sensorthat should be left exposed (e.g., to detect light, sound, moisture,temperature, etc.), then protective cover 130 may be shaped so thatdevice 28 is exposed.

FIG. 25 shows an example in which strands 80 are threaded throughtrenches 134 that are formed along either side of interposer 36. Theupper and lower protective covers 130 protrude beyond the outer edges ofinterposer 36, thereby forming trenches 134. Protective cover 130 on oneside of interposer 36 forms a first sidewall of each trench 134, andprotective cover 130 on an opposing side of interposer 36 forms a secondsidewall of each trench. Solder or other conductive material 142 may beused to electrically and mechanically couple strands 80 to pads 40 intrenches 134.

It may be desirable to further increase the mechanical robustness of theconnection between strands 80 and component 26 by embedding strands 80within a material in trenches 134. For example, strands 80 may beembedded within solder, polymer, epoxy, other material, or a combinationof materials that help to enclose strands 80 within trenches 134.

FIGS. 26-28 show an illustrative process for enclosing strands 80 withintrenches 134 using thermoplastic material and solder.

In the step shown in FIG. 26, solder 142 (e.g., solder paste, pre-applysolder, or preform solder) is formed in trenches 134 over pads 40.Strands 80 are then inserted into trenches 134 over solder 142.

In the step shown in FIG. 27, a thermoplastic structure such asthermoplastic structure 146 having protruding portions that match theshape of trenches 134 is press-fit onto protective cover 130 so that theprotruding portions of thermoplastic structure 146 extend into trenches134 of protective cover 130. This causes thermoplastic structure 146 topress strands 80 against solder 142 and pads 40 in trenches 134, therebyensuring electrical contact between pads 40 and strands 80.Thermoplastic structure 146 may be formed from a thermoplastic materialsuch as ethylene-vinyl acetate, acrylic, polyethylene, or other suitablethermoplastic material.

In the step shown in FIG. 28, heat may be applied to melt thermoplasticstructure 146 and reflow solder 142, thereby forming a solder jointbetween strand 80 and pad 40 while also sealing the solder joint withthermoplastic material 146. Heat may be applying using inductionheating, hot air, resistive heating, or other heating techniques. Insome scenarios, heating of solder 142 may cause strands 80 to penetratedown into the molten solder 142 such that solder 142 fully surrounds thediameter of strand 80. Once cool, thermoplastic 146 and solder 142 mayharden, leaving strands 80 securely embedded within solder 142 andthermoplastic 146. Thermoplastic 146 may protect the solder joint frommechanical damage and environmental contaminants.

FIGS. 29-33 show another illustrative process for enclosing strands 80in trenches 134 using solder and thermoplastic material.

In the step shown in FIG. 29, trenches 134 may be formed in protectivecover 130 to expose contact pads 40 on interposer 36. Solder 142 (e.g.,solder paste, pre-apply solder, or preform solder) may be placed intrenches 134 over pads 40.

In the step shown in FIG. 30, thermoplastic material 148 may bedeposited in trenches 134 over solder 142. Materials that may be used toform thermoplastic material 148 include ethylene-vinyl acetate, acrylic,polyethylene, or other suitable thermoplastic material.

In the step shown in FIG. 31, trenches 150 may be formed inthermoplastic material 148. Trenches 150 may be formed using laserequipment, machining equipment, or other suitable equipment. This is,however, merely illustrative. If desired, thermoplastic material 148 maybe deposited in trenches 134 around a structure that is then removed,thereby leaving openings 150 in thermoplastic material 148. Trenches mayalso be formed in solder 142, if desired. The example of FIG. 31 ismerely illustrative.

In the step shown in FIG. 32, strands 80 may be placed within trenches150 (which in turn are located in trenches 134).

In the step shown in FIG. 33, heat may be applied to melt thermoplasticmaterial 148 and reflow solder 142. Heat may be applying using inductionheating, hot air, resistive heating, or other heating techniques. Whensolder 142 becomes molten, strands 80 may sink down into solder 142, asshown in FIG. 33. When thermoplastic 148 melts, it spreads across trench134 (thereby closing opening 150 that was made in thermoplastic 148 inthe step of FIG. 31). After thermoplastic 148 and solder 142 havecooled, strands 80 will be firmly embedded in solder 142, and hardenedthermoplastic material 148 may form a seal over the electricalconnection between strand 80 and pad 40.

The order of steps described in connection with FIGS. 29-33 are merelyillustrative. For example, solder 142 may be reflowed to form a solderjoint between strands 80 and pads 40 before thermoplastic material 148is deposited in trenches 134 and melted to seal the solder joint. Ifdesired, customized heating techniques may be used depending on whichmaterial is being targeted (e.g., a first heating method may be used toreflow solder and a second heating method may be used to subsequentlymelt thermoplastic material 148).

FIG. 34 shows how a transducer may be used during the attachment process(e.g., an attachment process of the type shown in FIGS. 26-28 or of thetype shown in FIGS. 29-33) to help guide strands into trenches oncomponent 26. As shown in FIG. 34, component 26 may be placed betweenportions of fabric 12. Without line-of-sight capability during theattachment process, it may be challenging to guide strands 80 of fabric12 into trenches 134 and attach strands 80 to pads 40 on interposer 36.To help guide strands 80 into trenches 134, a transducer such astransducer 154 may be used to help press fabric 12 against component 26during the attachment process. The force applied on fabric 12 fromtransducer 154 causes strands 80 to fall into trenches 134.

If desired, transducer 154 may be used during the heating process (e.g.,when solder 142 is being reflowed and/or when thermoplastic 148 is beingmelted in trenches 134). In the example of FIG. 34, induction coil 152is used to inductively heat conductive structures in component 26. Forexample, induction coil 152 may be used to inductively heat solder 142,conductive portions of strand 80, and/or other metal elements incomponent 26. The heating of conductive elements in component 26 may inturn cause thermoplastic 148 to melt and spread across trenches 134(e.g., as described in connection with FIGS. 28 and 33). When transducer154 is used during the heating process, strands 80 may be guided intotrenches 134 and may sink down into molten solder 142. After solder 142and thermoplastic 148 have cooled and hardened, strands 80 may bemechanically and electrically coupled to pads 40 via solder 142, withthermoplastic 148 providing a seal that protects the connection frommechanical damage and environmental contaminants.

FIG. 35 shows an example in which a layer of thermoplastic 148 is usedto press down on strands 80 to help guide strands 80 into trenches 134during the attachment process. With this type of arrangement, solder 142may be placed on pads 40 in trenches 134, and strands 80 of fabric 12may be sandwiched between component 26 and thermoplastic structure 148.Thermoplastic structure 148 may be brought into contact with protectivecover 130, forcing strands 80 into trenches 134. Heat may then beapplied to reflow solder 142 and melt thermoplastic 148 in trenches 134,thereby creating a robust mechanical and electrical connection betweenstrand 80 and pad 40 (e.g., a connection of the type shown in FIGS. 28and 33).

If desired, thermoplastic structure 148 and/or protective cover 130 mayhave a shape that helps contain solder 142 and strands 80 in trenches134 during the attachment process. For example, thermoplastic structure148 and/or protective cover 130 may form sloped sidewalls in trenches134 or may have localized peaks surrounding trenches 134 to create deeprecesses that are more difficult for solder 142 or strands 80 to escapeduring the attachment process.

As shown in FIG. 36, for example, thermoplastic 148 may have localizedpeaks 156 (e.g., raised portions) surrounding trench 134 to essentiallyincrease the depth of trench 134 (e.g., so that the depth of trench 134is greater than the thickness of protective cover 130). The increaseddepth of trenches 134 may help maintain solder 142 and strands 80 intrench 134 during the attachment process. When heat is applied to reflowsolder 142 and melt plastic 148, peaks 156 may melt into trenches 134,resulting in a sealed electrical and mechanical connection betweenstrands 80 and component 26 (e.g., a connection of the type shown inFIGS. 28 and 33).

FIGS. 37-43 show illustrative examples of trench geometries and padsizes that may be used in component 26 to help attach component 26 tostrands 80 of fabric 12. It should be understood that component 26 mayhave any suitable combination of features shown in FIGS. 37-43 (e.g.,the trench shape of FIG. 39 may be used with the pad size of FIG. 38,etc.). The combinations of features shown are merely illustrativeexamples.

In the example of FIG. 37, protective cover 130 forms straight sidewallsof trench 134 (e.g., sidewalls that extend perpendicular to the uppersurface of interposer 36), and the width of pad 40 is smaller than thewidth of trench 134.

In the example of FIG. 38, protective cover 130 forms sloped sidewallsof trench 134, where the width of trench 134 may be smaller at thebottom of trench 134 than at the top of trench 134. The width of pad 40may be greater than the width of the bottom of trench 134.

In the example of FIG. 39, protective cover 130 forms sloped sidewallsof trench 134, where the width of trench 134 may be greater at thebottom of trench 134 than at the top of trench 134. The width of pad 40may equal to the width of the bottom of trench 134. The reduced width oftrench 134 at the top of trench 134 may help contain solder 142 andstrand 80 in trench 134.

In the example of FIG. 40, solder 142 has a shape that helps “grab”strands 80 to keep strands 80 in trenches 134 during the attachmentprocess. Solder 142 may, for example, have the shape of barbs, hooks,spurs, spikes, or other suitable shape. When heat is applied to reflowsolder 142, solder 142 may consolidate into a bead-like shape thatsurrounds strands 80.

FIGS. 41-43 show bottom views of protective cover 130 having varioustrench shapes and pad arrangements.

In the example of FIG. 41, trenches 134 have a straight shape anduniform width across protective cover 130. Each pad 40 may have anelongated shape in trenches 134, creating a large area with which toattach strands 80 to pads 40.

In the example of FIG. 42, trenches 134 have locally widened portions toaccommodate larger pads 40. The use of locally widened portions may helpcontain solder 142 on pad 40. For example, the reduced width of trench134 outside of the regions where pads 40 are located may help preventsolder from straying from pad 40. If desired, a solder mask may be usedin regions of trenches 134 without pads 40 to help prevent solder 142from reaching those areas. FIG. 42 also shows how pads 40 and locallywidened portions of trenches 134 may be staggered relative to oneanother. By staggering pads 40, the width of trenches 134 may beincreased to accommodate larger pads 40. This type of arrangement mayalso allow for a greater density of pads 40 on component 26 and asmaller strand-to-strand pitch.

FIG. 43 shows an example in which the width of trench 134 is wider atthe outer edges of protective cover 130 than at the center of protectivecover 130. The locally widened portions of trench 134 at the edges ofprotective cover 130 may allow strand 80 to bend or change directiongradually as it exits trench 134 and prevent sharp corners of protectivecover 130 from damaging strand 80.

The foregoing is merely illustrative and various modifications can bemade by those skilled in the art without departing from the scope andspirit of the described embodiments. The foregoing embodiments may beimplemented individually or in any combination.

What is claimed is:
 1. A method for attaching an electrical component tofabric having a conductive strand, wherein the electrical component hasa trench and a contact pad in the trench, the method comprising:depositing solder in the trench; inserting a conductive strand into thetrench; inserting thermoplastic material into the trench; and applyingheat to reflow the solder and melt the thermoplastic material in thetrench.
 2. The method defined in claim 1 wherein the electricalcomponent comprises a protective cover and wherein the trench is formedin the protective cover.
 3. The method defined in claim 2 wherein theprotective cover comprises thermoplastic.
 4. The method defined in claim1 wherein applying heat comprises inductively applying heat with aninduction coil.
 5. The method defined in claim 4 further comprising:with a transducer, applying force to press the fabric and the electricalcomponent together to guide the conductive strand into the trench. 6.The method defined in claim 1 wherein the thermoplastic materialcomprises a protrusion and wherein inserting the thermoplastic materialinto the trench comprises inserting the protrusion into the trench. 7.The method defined in claim 1 further comprising: inserting theelectrical component into a pocket in the fabric.
 8. The method definedin claim 1 wherein the thermoplastic material has an opening and whereininserting the conductive strand into the trench comprises inserting theconductive strand through the opening and into the trench.
 9. The methoddefined in claim 8 wherein applying heat comprises applying heat toclose the opening in the thermoplastic material such that the conductivestrand is enclosed within the trench.
 10. A method for attaching anelectrical component to fabric having a conductive strand, wherein theelectrical component has a trench and a contact pad in the trench, themethod comprising: depositing solder into the trench; insertingthermoplastic into the trench; inserting the conductive strand into anopening in the thermoplastic material and into the trench; and applyingheat to reflow the solder and melt the thermoplastic material in thetrench.
 11. The method defined in claim 10 wherein the electricalcomponent has a protective structure and wherein the trench is locatedin the protective structure.
 12. The method defined in claim 10 whereinapplying heat comprises applying heat to close the opening in thethermoplastic material such that the conductive strand is enclosedwithin the trench.
 13. The method defined in claim 10 wherein theprotective structure comprises thermoplastic.
 14. The method defined inclaim 10 wherein applying heat comprises applying heat throughinduction.
 15. A method for attaching an electrical component to fabricduring formation of the fabric, wherein the fabric has a conductivestrand and the electrical component has a contact pad and a protectivestructure with a trench that exposes the contact pad, the methodcomprising: depositing solder into the trench; inserting the conductivestrand into the trench; and applying heat to reflow the solder andelectrically connect the conductive strand to the contact pad in thetrench.
 16. The method defined in claim 15 further comprising: insertingthe electrical component into a pocket in the fabric.
 17. The methoddefined in claim 16 further comprising: inserting thermoplastic materialinto the trench, wherein applying heat comprises applying heat to meltthe thermoplastic material in the trench.
 18. The method defined inclaim 17 wherein the solder forms a solder connection between theconductive strand and the contact pad and wherein the thermoplasticmaterial seals the solder connection.
 19. The method defined in claim 17further comprising: forming an opening in the thermoplastic material,wherein inserting the conductive strand into the trench comprisesinserting the conductive strand through the opening and into the trench.20. The method defined in claim 19 wherein applying heat comprisesapplying heat to close the opening in the thermoplastic material suchthat the conductive strand is enclosed within the trench.